Speed-goverited stopping mechanism



G. E. MOLYNEUX. SPEED oovemvso STOPPING MECHANISM.

APPLICATION FILED AUG. 3h l9l5.

Patented Nov. 11, 1919.

3 SHEETS-SHEET 1- WITNESS:

G. E. MOLYNEUX.

,SPEED GOVEBNED STOPPING MECHANISM.

APPLICATION FILED Avast, I915 1,321, 1 l 8. Patented Nov. 11, 1919.

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wnwtss APPLICATION FILED AU SPEED GOVERNED STOPPI G MECHANISM.

3 SHEETSSHEET 3- /Q 1 INVENTOR A 7TOR/VEKS Patented Nov. 11, 1919.

GEORGE E. MQLYNEUX, 0F BAYONNE, NEW JERSEY.

SPEED-GOVERNED STOPPING MECHANISM.

Specification of Letters Patent.

Patented Nov. 11, 1919.

Application filed August 31, 1915. Serial No. 48.191.

To all whom it may, concern:

, Be it known that 'I, GEORGE E. MOLYNEUX, a citizen of the United States, and residing in the city of Bayonne, county of Hudson, in the State of New Jersey, have invented certain new and useful Improvements in Speed Governed Stopping Mechanisms, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

The immediate purpose of this invention is to produce an improved mechanism for arresting quickly the motion ofhigh speed sewing machines without shock or jar or undue wear, but the invention, as will be perceived, is applicable to other machines. In all stopping mechanisms of the same general character as that in which the present in vention is embodied there is, of course, some part the position or movement of which is 'cetermined or controlled by the speed of the machine to which the mechanism is applied, such part, by its position or movement, determining the operation of the stopping devices so that'such devices shall not become effective until the speed of the machine has fallen below a predetermined rate, which may be dependent upon the character of the work being performed. In the earlier efforts to produce a stopping mechanism of this character reliance was placed upon a movable dog which was held, bycentrifugal force, at aspeed above that predetermined for the operation of stopping devices, out of the path of a stop, but was moved by a spring into the path of such stop as the speed fell below the predetermined rate. In

7 such devices the movable dog moved gradually into the path of the stop asthe speed diminished, with the result that the do was successively sheared off as the speed gradiially diminished so that the niechanisn qiiicltly became inoperative. In later forms of-such mechanism, designed to overcome the difficulty just referred" to, there were two parts, one ofwhichfwas relatively fixed while the other was rotatable with the shaft, arranged so that one of such parts mightbe moved, in an axial direction, into engagement of the other of such parts, by the action of a device acted upon by centrifugal force in opposition to a spring; These later forms proved ta sa ss s e O e ates u e quired rather strong springs, developed considerable friction between the relatively movable parts, were somewhat complicated in construction, and were not so constructed that they could be applied readily to existing machines. The improved mechanism in which the present invention is embodied is designed so as to overcome the difficulties incident to the use of both types ofmechanisms referred to and so as to be complete in itself and capable of application without dificulty to existing machines. The particular form ofthe mechanism which has been chosen for illustration herein is designed particularly for use with straightaway sewing machines as distinguished from machines which are intended to be stopped automatically after a given number of stitches. It is further designed so that it may be adjusted readily by the operator to insure the arresting .of the movement of the sewing machine with the needle-bar in its highest position regardless of the character of the material being sewed. In accordance with the invention a radially movable block, carried with the rotating shaft and subject to the action of the centrifugal force supports, at all speeds above the predetermined limit at which the stopping mechanism shall act, aradially movable but non-rotatable carrier with a stop-lug out of the path of a co-acting shoulder which rotates with the shaft; and when the speed falls below the predetermined limit the centrifugal block yields to spring pressure applied to the carrier and the StOP-lllg carried thereby is permitted to move into the path of the coacting lug on the rotatable part. Suitable provislon is made so that the maximum force is required to start the centrifugal block from its normal or inoperative position in order that the stop-lug shall be moved instantly, rather than gradually, into its full operatlve position and all shearing action be thereby avoided. The invention will be more fully explained hereinafter with reference to the accompanying drawings 1n which is illustrated a convenient and practical embochment of the invention, and in which,-

Figure 1 is a view in front elevation showing the improved stopping mechan smapplied to the arm of the sew ng machine.

' Fig. 2 is a view of the same n end elevation as seen from the right hand in Fig. 1, with a portion of the driving pulley broken away to disclose the parts beyond it..

Fig. 3 is a view of the same parts in longitudinal section.

Fig. 4: is a view in section on the plane indicated by the line 44 of Fig. 3, looking in the direction of the arrow.

Fig. 5 is a perspective view of the centrifugal block.

Fig. 6 is a view of the mechanism partly in horizontal section and partly as seen from above.

F ig. 7 is a view in section on the plane indicated on the line 77 of Fig. 6, looking in the direction of the arrow.

The improved stopping mechanism is shown in the drawings as applied directly to the arm a of an ordinary sewing machine, the arm having the hub a which furnishes a. bearing for the usual shaft 1) and also serves, in conjunction with the shaft, as a support for the stopping mechanism. No other adaptation of any ordinary sewing machine than the shaping of this hub is necessary to permit the stopping mechanism to be applied thereto, so that such stopping mechanism may be made up as a unit complete in itself and sold directly to the user of the sewing machine to be applied thereto.

To permit the stopping mechanism to be applied directly to the arm of the sewing machine, and also to provide for the suit able cushioning of the stopping mechanism, there is first secured rigidly to the hub a, as by means of a set s rew 0, a ring a, which is provided at a suitable point with a radial lug 0 To the ring '0 is secured frictionally, and so as to be capable of a limited rotary movement, a disk (Z. As shown particularly in Figs. 6 and 7 this disk cl is provided with arc-shaped slots at through which headed screws d are passed into the ring 0, whereby the disk (Z is held frictionally against the fixed ring 0. On the left hand face of the disk (Z are formed spring abutments (Z and d, between which stands the radial lug c of the fixed ring 0- A relatively heavy spring 0 is interposed between the radial lug 0 and the abutment CF to cushion the stopping mechanism, and between the radial lug c and the abutment (Z is interposed a relatively lighter spring 6 to cushion the recoil.

The usual hand wheel and driving pulley having been removed from'the shaft 1), there is substituted therefor a sleeve f which is secured rigidly to the shaft I), as by a set screw 7, and carries at one end the driving pulley f and at the other end the disklike rotatable member of the stopping mechanism. This rotatable member f is slotted radially, as shown at f in Fig. 4, to receive the centrifugal block 9, which is shown in detail in Fig. 5. This block is held 1101'- mally in its outer position by a light spring 9, shown in Fig. 3, regardless of the position of the rotatable member 7 or its speed. It is adapted to move in a truly radial direction with respect to the shaft 6 and ro tatable member P, so that its sides, for a portion of their length, are parallel, as atg while the sides of the radial slot 7 are also parallel for a portion of their length, as at 7. The outer portions of the sides of the block 9, however, are inclined toward each other, as at 9 (that is, the block is tapered), and the outer portions f of the sides of the radial slot f are also inclined inwardly at the same angle, which is such that there can be no wedging action between the block and the sides of the slot; however, the portions of the sides of the block and the portions 7 of the sides of the slot, being perfectly plane and smooth surfaces of metal, adhere slightly to each other when the block is in its extreme outward position, or are held together by atmospheric pressure, so that the maximum of pressure is required to start the block from its extreme outer position, while its continued movement is resisted only by the light spring 9. This is important to prevent the gradual inward movement of the detector pin, hereinafter referred to, and its possible shearing. The block 9 is retained in the slot 7 by a keeper 7.

The extreme outer edge 9 of the centrifugal block 9 is curved on the same radius as the disklike rotatable part i and fills completely the gap formed by the slot in the periphery of the disklike rotatable part i and forms with such 7 eriphery a practically continuous and unbro en circular track. On this track, when the machine is rotating at a speed above the predetermined limit, rests a detector pin it which is preferably mounted yieldingly, by means of a stem h and encircling spring h in a carrier 2'. The purpose in mounting the pin it yieldingly is to permit it to yield readily to any break in the continuous track on which it rests which might exist at the edge of the radial slot 7. This pin may be hardened as well as the peripheral track on which it rests,

so that the friction between the two is neg lig'ible. The pin is guided readily in a radial aperture (Z formed in the overhang.- ing flange (Z of the disklike member .(Z.

The carrier 6, which constitutes adevice for coupling the relatively stationary member cl and therotatable member f to arrest the motion of the latter, is guided for radial movement on the member d by radial slots (Z and d and carries'the radial stop lug z" for cooperation with the corresponding stop lug 7, which is secured to the rotatable member 7. The carrier receives the pressure of a spring is which tends to press, the

55 movabl y on the rotatable member, and a carrier inward against the centrifugal block 9 and the spring is provided with an adjusting screw is, easily accessible, so that the pressure maybe regulated according to the character of the work being performed. By adjusting the pressure of this spring it is possible to vary the limit of speed at which the stopping mechanism will operate, for if the pressure of the spring be increased the detector pin it will overcomethe centrifugal force which acts upon the block 9, in addition to the spring g, at a lower speed of rotation of the shaft than it would if the speed were higher. In this man'- ner it is possible to regulate the stopping'mechanism according to the character of the fabric being sewed and the friction of the needle in passing through it so that the movement of the machine shall be are rested, as is desirable, when the needle-bar is in its highest position.

In order that the operator may start the machine, a fork m, having cam-fingers m to engage pins 2' on the sides of the carrier 2', is mounted on the sleeve f so as to be movable in a longitudinal direction thereon, and is engaged by a bell-crank lever n which is connected in the usual manner, as by a spring a and link W, with the usual controlling trea'dle. A light spring 0 acts against the fork min opposition to the bell crank a. Pressure of the operators foot on the treadle effects the coupling of the transmission in the usual manner and at the same time actuates the bell-crank lever n to move the fork m against'the spring 0 and cause the fingers m to withdraw the carrier 2' and the stop lug 1," sdthat the machine is free to operate, while release of the pressure of the operators foot causes the uncoupling of the usual transmission and the withdrawal of the fingers mfrom underneath the pin 2' so that the stop mechanism may operate as soon as the speed falls below the predetermined limit.

It will be understood that various changes may be made in the details of construction and arrangement to suit the different uses and convenienceof the'manufacturer without departing from the spirit of the invention. a

I claim as my invention:

1. In a stopping mechanism, the combination of a relatively fixed member, a rotatable member, a centrifugal body mounted coupling device mounted movably on one of said members to prevent relative rotation of said members and adapted to engage the other of said members," and held normally in inoperative position by said centrifugal body.

2. In a stopping mechanism, the combination of a relatively fixed member, a rotatable member, a centrifugal body mounted movably on one of said members, a coupling device mounted movably on one of said members and adapted to engage the other of said members to prevent relative rotation of said members and held normally in inoperative position by said centrifugal body, and means to move said coupling device in opposition to the action of the centrifugal body.

3. I11 a stopping mechanism, the combination of a relatively fixed member, a rotatable member, a centrifugal body mounted movably on the rotatable member, a coupling device mounted movably on one of said members and adapted to engage the other of said members to prevent relative rotation of said members and held normally in inoperative position by said centrifugal body, a'spring acting upon said coupling device to move the same in opposition to the action of the centrifugal body, and means to adjust the pressure of said spring.

4. In a stopping mechanism, the combination of 'a relatively fixed member, a rotatablemember, a centrifugal body mounted Ino'vably on the rotatable member, a coupling device mounted movably on one of said members and adapted to engage the other of said members to prevent relative rotation of said members and held normally in inoperative position by said centrifugal body, andv means to disengage said coupling device from the other of said members. 5. In a stopping mechanism, the combination of a relatively fixed member, a rotatable member, a centrifugal body mounted movably on the rotatable member, a coupling device mounted movably on one of said members and adapted to engage the other of said members to preventrelative rotation of said members and held normally in inoperative position by said centrifugal body, a device to withdraw the coupling device from engagement with the other of said members, means under the control of the operator to actuate said device in one direction, and a spring to actuate said device in the opposite direction.

6. In a stopping mechanism, the combination of a relatively fixed member provided with means to permit limited movement thereof, means to cushion such rotary movement, a rotatable member, a radially movable coupling device to connect one of said members with the other, and centrifugally controlled devices to control said coupling device.

7. In a stopping mechanism, the combination of a collar adapted to be secured to the arm of a sewing machine co-axially with the shaft, and, a stopping mechanism secured to said collar and comprising a relatively fixed memberco-axial with the shaft, a rotatable member eo-axial with the shaft, a centrifugalbody mounted movably on the rotatable member, and a coupling device mounted movably on one of said members to prevent relative rotation of said members and adapted to engage with the other of said members, and held normally in inoperative position by said centrifugal body.

8. In a sto ping mechanism, the combination of a re atively fixed member co-axial with the driven shaft, a disklike member secured to the driven shaft and having a radial slot, a centrifugal body mounted in said slot and normally filling the gap in the periphery of the disklike member, and a coupling device movable radially on the relatively fixed body and adapted to en gage the disklike member to arrest the rotation of the shaft and held normally out of engagement therewith by 'said centrifugal body.

9. In a stopping mechanism, the combination of a relatively fixed member co-axial with the driven shaft, a disklike member secured to the driven shaft and having a radial slot with inwardly inclined sides, a centrifugal body mounted in said slot and having inwardly inclined sides and normally filling the gap in the periphery of the disk like member, and a coupling device movable radially on the relatively fixed body and adapted to engage the disklike member to arrest the rotation of the shaft and held normally out of engagement therewith by said centrifugal body.

10. In a stopping mechanism, the combination of a relatively fixed member co-axial with the driven shaft, a disklike member secured to the driven shaft and having a radial slot with inwardly inclined sides, a centrifugal body mounted in said slot and having inwardly inclined sides and normally filling the gap in the periphery of the disklike member, a coupling device movable radially on the relatively fixed body and adapted to engage the disklike member to arrest the rotation of the shaft and held normally out of engagement therewith by said centrifugal body, and a spring bearing on said coupling device to move the same in opposition to the action of the centrifugal body.

11. In a stopping mechanism, the combination of a relatively fixed member co-axial with the driven shaft, a disklike member secured to the driven shaft and having a radial slot and an abutment, a centrifugal body mounted in said slot and normally filling the gap in the periphery of the disklike member, and a carrier supported for radial movement on the relatively fixed body and having a stop lug adapted to engage said abutment, and having also a detector pin bearing on the periphery of said disklike member and the outer edge of the centrifugal body, and holding the carrier with its stop lug out of engagement with said abutment.

12. In a stopping mechanism, the combination of a relatively fixed member co-axial with the driven shaft, a disklike member secured to the driven shaft and having a radial slot and an abutment, a centrifugal body mounted in said slot and normally filling the gap in the periphery of the disklike member, a carrier supported for radial movement on the relatively fixed body and having a stop lug adapted to engage said abutment, having also a detector pin bearing on the periphery of said disklike member and-the outer edge of the centrifugal body and holding the carrier with its stop lug out of engagement with said abutment, and a spring bearing on said carrier to move the same in opposition to the action of said centrifugal body.

13. In a stopping mechanism, the combination of a relatively fixed member coaxial with the driven shaft, a disklike member secured to the driven shaft and having a radial slot and an abutment, a centrifugal body mounted in said slot and normally fill ing the gap in the periphery of the disklike member, a carrier supported for radial movement'on the relatively fixed body and having a stop, lug adapted to engage said abutment, having also a detector pin bearing on the periphery of said disklike member and the outer edge of the centrifugal body and holding the carrier with its stop lug out of engagement with said abutment, a spring bearing on said carrier to move the same in opposition tothe action of said centrifugal body, and means to adjust said spring.

14. In a stopping mechanism, the combination of a relatively fixed member co-axial with the driven shaft, a disklike member secured to the driven shaft and having a radial slot and an abutment, and a centrifugal body mounted in said slot normally filling the gap in the periphery of the disklike member, a carrier mounted for radial move ment on the relatively fixed member and having a stop lug for engagement with said abutment, and having also a detector pin bearing normally on the continuous track formed by the periphery of the disklike member and the centrifugal body and holding the stop lug out of engagement with the V abutment, said carrier having also a trans verse pin, a cam-finger adapted to be thrust beneath said pin to withdraw the carrier, and means to move said cam-finger.

15. In a stopping mechanism, the combination of a relatively fixed member, a rotatable member, a radiallymovable coupling device to connect one of said members with the other to prevent relative rotation ofsaid members, and centrifugally controlled detable member to effect an engagement between the relatively fiXed member and the rotatable member for the purpose of pre ventingrelative rotation of said members. This specification signed this 26th day of August, A. D. 1915.

GEORGE E. MOLYNEUX.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0. 

